A court appeal by a couple who were fined in Switzerland for keeping their daughters out of mandatory mixed-gender school swimming lessons for reasons linked to their Muslim faith has been rejected.

The European Court of Human Rights decision upholds a Swiss federal court ruling that education officials had not violated the Turkish-born family's rights of freedom of conscience and religion in the case in Basel dating back to 2008.

In a summary of the ruling announced on Tuesday, the European court based in Strasbourg acknowledged "interference" in freedom of religion - but that public school had a "special role" in integration, particularly of children of foreign origin.

Such issues of compulsory public education and religious belief have prompted similar cases in neighbouring Germany and Liechtenstein in recent years.

Under Basel school system rules, attending swimming classes is mandatory for all school pupils and exemptions are possible only once they reach puberty.

The girls were aged seven and nine when their parents first became aware that no exemption was allowed, according to the ruling.

The court noted that Swiss authorities had taken steps to ease the family's concerns, such as by allowing for individual, separate showers and allowing for the wearing of a "burkini", or body-covering swimwear used by some Muslim women.

The girls' mother refused that option, arguing that "the burkini didn't erase the contours" of their bodies - and the family believed that wearing one would "stigmatise" its wearer, the ruling said.

The parents kept their daughters out of the swimming classes.

Two years after the case emerged, education officials in Basel ordered the family to pay a total of 1,400 Swiss francs (about £1,150 today) for repeatedly violating the rules.